Molecular Structure of the Photo-Oxidation Product of Ellagic Acid in Solution

The photoreaction
of the antioxidant ellagic acid (EA) elicits a drastic
coloration in solution from colorless to yellow
in aerated tetrahydrofuran, which appears as a new absorption band
at 405 nm. Analysis of the X-ray crystal structure suggests that the
photo-oxidation product of EA is a multiple cleavage
π-structure (Ox-EA) that results from the interaction
of EA with singlet oxygen followed by sequential cleavage
and rearrangement steps.